in the example. The pinion K can slide on shaft z, and so keeps
always in gear with L, being driven by a feather key. Length of
stroke is adjusted by the position of P, but position of ram is
given by adjustment of the nut Q.
The table R, supporting the work (which is bolted to top or
side as found convenient), may be adjusted for height by the
handle s, which, by mitre gear T, rotates the screw within the nut
u, fixed to the bracket v. The horizontal position of the work
may be varied by moving v along the bed to the point required.
w is a mandrel upon which hollow cylindrical work may be
placed by removing the loose collar x, and gripping the work
between the cones, The bracket Y steadies the end of the mandrel.
Three feeds are required, each of which may be worked by
hand if desired The pinion 4 (Fig. 1740) drives wheel & carried
on a stud <?. An adjustable crank pin on g is connected to the
lever ^, which gives, through ratchet d} an intermittent rotation to
the spindle/. Upon this spindle is a worm gearing into a worm
wheel on the mandrel w, and thus a rotary feed is conveyed to
the mandrel. The latter may be used for such articles as lever
bosses, which are interrupted on one side by the lever arm, and
therefore unsuitable for lathe work. The second feed is a
horizontal motion of the saddle for work fixed on the table. A
crank pin /£, on the wheel L, is connected to the ratchet m, and
the motion transmitted by n to the wheel j>. p forms a nut
attached to the saddle, and as the screw q is fixed to the bed, it is
evident that a rotation of/ will advance the saddle along the screw.
The third feed is vertical, r is a bracket fixed to the saddle,
and s a rod sliding in r, as -well as in brackets //carried an the
ram. At each back stroke of the latter the tappet a/, on rod
r, is caught by the bracket r, and s is moved to the left, causing
the ratchet gear x to turn the screw y, and give a small vertical
advance to the tool box. When the ram reaches the end of the
advance stroke the tappet z in turn catches ^, moving s back to its
original position. The head A can be fixed at an angle to the
vertical by unclamping bolts 2 2, and refking, vrhen the last-
mentioned ffeed becomes angular; and the position of the tappets
may also be varied.
In addition to the abore, a fourth movement, enabling us to
fix the tool box at an angle while preserving the -vertical feed, is